There are fewer Google searches on mental illness when summer is in full bloom.

When the sun’s out and your mood lifts after a seemingly interminable winter, you’re not imagining it if you think you feel better and brighter. Seasonal Affective Disorder (SAD) may be more prevalent than previously believed.

Searches on Google suggest that mental illness may have strong links with seasonal patterns, according to research by the Graduate School of Public Health at San Diego State University. Previous studies on mental illness patterns have been done by phone, but may not have been accurate because people can be reluctant to reveal the state of their mental health. But the researchers were able to monitor passively the queries people typed in to Google’s search engine.

The research team monitored mental health queries in the US and Australia between 2006 and 2010. The findings were grouped according to type of mental illness. They found that mental health queries were “consistently higher in winter than in summer”. Examples of this include:

Summer searches for eating disorders are down 37% in the US and 42% in Australia compared with winter.

Searches for suicide are 24% lower in the US and 29% lower in Australia in the summer.

Bipolar Disorder searches are down 16% and 17% in the US and Australia respectively during summer months.

“We didn’t expect to find similar winter peaks and summer troughs for queries involving every specific mental illness or problem we studied. However, the results consistently showed seasonal effects across all conditions,” says James Niels Rosenquist, a psychiatrist at Massachusetts General Hospital.

The researchers plan to look at other mental illness trends – even down to patterns in mental illness queries on different days of the week.